Intimate partner violence (IPV) is a serious public health problem in the U.S. Although the precise etiologic role of substance use has not been established, considerable empirical evidence links alcohol and drug use on the part of the male, female, or both with IPV occurrence and severity. Neighborhood contextual factors, such as poverty and unemployment, also have been associated with elevated risk of IPV. The research literature, however, has not adequately addressed whether neighborhood characteristics, such as poverty, high unemployment, and low collective efficacy, mediate or moderate the relationships between drugs, alcohol, and IPV such that these relations are stronger for couples residing in neighborhoods characterized by these factors. Additionally, few studies have assessed the contribution of male and female drug use to IPV perpetration and victimization among general household population samples. This study will address these issues using data from two national samples of married and cohabiting respondents in which information was obtained on substance use, IPV, and neighborhood characteristics. The proposed study will conduct a secondary analysis of data from the National Study of Couples (NSC) and the National Household Survey on Drug Abuse (NHSDA). The NSC was the first in-depth national study of the association between alcohol and IPV among African-American, Hispanic, and white couples, and contains Census-based information on the socioeconomic characteristics of the couples' neighborhoods. The NHSDA annually obtains data on the prevalence and incidence of illicit drug, alcohol, and tobacco use in the civilian population, and contains information on neighborhood characteristics and marital aggression. In addition to self-report data, the NHSDA will link Census-based data, such as poverty and unemployment levels, to individual records. Both the NSC and the NHSDA provide an excellent opportunity to address a number of important research gaps on the contribution of drug use to IPV risk among couples in the general household population, and whether neighborhood contextual factors mediate or moderate these relationships. Findings of this study will help to inform environmentally-based IPV prevention strategies. [unreadable] [unreadable]